Upgrading an appliance to use the DHCP configuration mode

Using CA AppLogic® › Appliance Developer Guide › Appliance Kit › How to Upgrade Your Applications to Use the New Appliance Kit (APK) › Upgrading an Appliance to Use the DHCP Configuration Mode

Upgrading an Appliance to Use the DHCP Configuration Mode

Complete the following steps to upgrade an existing Linux appliance from volfix to DHCP configuration mode for either a catalog class or singleton.

Perform these steps:

Make an application that contains a singleton copy of the appliance you want to upgrade:
- If the appliance is in a catalog, create a new application that contains an instance of the catalog class and branch the instance to create a singleton.
- If the appliance is a singleton:
  - If the application containing the singleton is running, you must stop the application.
  - Copy the application that contains the singleton using the app copy command. The singleton should be upgraded in its own application in case something goes wrong the original singleton is preserved. All of the remaining steps in this section should be executed over the new copy of the application.
  Note: If you do not want to make a copy of the application because it has very large volumes, you can convert the singleton into a catalog class and instantiate an instance of that class in a new application.
In the new application, if your appliance does not have its external interface enabled and configured, connect the singleton to a NET appliance to obtain external network access:
- If necessary, access the infrastructure editor and add a net terminal to the singleton.
  Mark this terminal as a gateway interface in the appliance boundary.
- Connect the net terminal of the singleton to the in terminal of the NET appliance instance.
- Configure the NET appliance with the appropriate network settings.
If the singleton has a read-only boot volume or any boot volume folders, such as /usr, residing on common, read-only volumes, convert these volumes to read/write. This conversion is required because the installation of various packages on the appliance could require updates to these volumes:
- Open the new application in the GUI. Right-click the singleton and select Modify Boundary.
- Select the Volumes tab.
- In the Type and Options columns, verify if common, read-only volumes exist. If there are no volumes of this type, proceed to Step 4.
- For all of the common, read-only volumes, clear the read-only (glasses icon) button. The read-only button has a picture of glasses.
Configure all mandatory properties and volumes of the singleton and start the application with the --debug option.
Install the dhclient package on the singleton (a dependency of APK).
For example, on a CentOS based appliance:
- ssh into the running singleton appliance
- Execute: yum install dhclient
Copy the appropriate APK to /tmp in the running singleton:
- Obtain the IP address of the DHCP server for the internal interface of the singleton appliance:
  - In the appliance shell, execute ifconfig -a and note the broadcast subnet of the last enumerated network interface.
    For example, the subnet is 10.47.255.255. The IP address for the DHCP server is identical, except for the last number which is one less. In this case, 10.47.255.254.
    
    If the broadcast subnet does not list a usable address, execute the following 2 steps:
    
    Execute dhclient -r ethX where X is the number of the last enumerated network interface. This removes the DHCP lease.
    
    Execute dhclient ethX and note the IP address from which DHCPOFFER is made
- Use wget to download the appropriate APK into your appliance: This downloads index.html containing the list of files that are downloadable from the grid controller. You can also use a text-based browser for convenience.
```
wget http://10.47.255.254:8080/download -
cat index.html; 
```
  Note the latest version of the APK package. For example, apk-2.0.20-linux-rh.tar.gz; 2.0.20 is the latest version as of CA AppLogic® 2.7
```
cd /tmp 
wget http://10.47.255.254:8080/download/apk-2.0.20-linux-rh.tar.gz - 
```
  Verify the IP and APK package
```
cd / 
```
Follow the appropriate APK installation instructions. It should not be necessary to replace the domU kernel.
Note: Do not delete the /appliance directory.
- If upgrading a CentOS-based appliance, execute the following:
```
cd / 
mv /appliance /appliance_save 
tmp/apk-install 
rm -f /tmp/apk-install /tmp/apk-2.0.18-linux-rh.tar.gz 
mv /appliance_save /appliance 
mkdir /var/log/appliance 
```
- For other operating systems other than CentOS, see the APK Installation for RedHat or Ubuntu Distributions section in the Appliance Developer Guide for detailed instructions.
If the singleton, such as a VDS application singleton, allows for password based ssh authentication, edit /etc/ssh/sshd_config and modify the following:
- Change PermitRootLogin without-password to PermitRootLogin yes
- Remove ChallengeResponseAuthentication no
To enable the original /appliance/appliance.sh script execute on appliance start:
- Create a file /etc/sysconfig/applogic_appliance with mode 644 which contains the following text:
```
/appliance/appliance.sh $@ 
```
In the infrastructure editor, view the singleton boundary and note any files listed in the Config Files tab, For example /etc/httpd/conf.d/appl.conf
- If no config files are listed, go to the next step.
- If config files are listed, create a file /etc/sysconfig/applogic_init with mode 644 containing a space separated list of config files (surrounded by double quotes), For example:
```
APK_CONFIG_FILES="/etc/httpd/conf.d/appl.conf /etc/httpd/conf.d/bnna.conf" 
```
Stop the application.
In the infrastructure editor, modify the singleton boundary:
- In the Config Files tab, delete all entries
- In the General tab, click the Virtualization Mode Options button and do the following:
  - Clear the Kernel Path and Initrd Path entries
  - Change the Configuration Mode from volfix to dhcp
- Save the application
Start the application in debug mode using the --debug option. The application starts.
- If the application fails to start, examine the grid controller system log or log list for details.
- Test the appliance to verify it works.
If the upgraded appliance had common, read-only volumes that were converted to read/write in step 3, please verify the volumes are converted back to read-only.
Your appliance is now upgraded to use the APK and the DHCP configuration mode.

If your upgraded appliance is a singleton, the upgrade process is complete.

If your appliance is a catalog class, refer to Upgrading applications to use your new DHCP-based appliances on how to upgrade your application to use the upgraded appliance.